995 resultados para ATLANTIC-FOREST LANDSCAPE


Relevância:

100.00% 100.00%

Publicador:

Resumo:

Abstract Background A descriptive study was carried out in an area of the Atlantic Forest with autochthonous malaria in the Parelheiros subdistrict on the periphery of the municipality of São Paulo to identify anopheline fauna and anophelines naturally infected with Plasmodium as well as to discuss their role in this peculiar epidemiological context. Methods Entomological captures were made from May 2009 to April 2011 using Shannon traps and automatic CDC traps in four areas chosen for their different patterns of human presence and incidences of malaria (anthropic zone 1, anthropic zone 2, transition zone and sylvatic zone). Natural Plasmodium infection was detected by nested PCR based on amplification of the 18S rRNA gene. Results In total, 6,073 anophelines were collected from May 2009 to April 2011, and six species were identified in the four zones. Anopheles cruzii was the predominant species in the three environments but was more abundant in the sylvatic zone. Anopheles (Kerteszia) cruzii specimens from the anthropic and sylvatic zones were positive for P. vivax and P. malariae. An. (Ker.) bellator, An. (Nys.) triannulatus, An. (Nys.) strodei, An. (Nys.) lutzi and An. (Ano) maculipes were found in small numbers. Of these, An. (Nys.) triannulatus and An. (Nys.) lutzi, which were collected in the anthropic zone, were naturally infected with P. vivax while An. (Nys.) triannulatus from the anthropic zones and An. (Nys.) strodei from the transition zone were positive for P. malariae. Conclusion These results confirm that Anopheles (Kerteszia) cruzii plays an important role as a major Plasmodium vector. However, the finding of other naturally infected species may indicate that secondary vectors are also involved in the transmission of malaria in the study areas. These findings can be expected to help in the implementation of new measures to control autochthonous malaria in areas of the Atlantic Forest.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The time required to regrowth a forest in degraded areas depends on how the forest is removed and on the type of land use following removal. Natural regeneration was studied in abandoned old fields after intensive agricultural land use in areas originally covered by Brazilian Atlantic Forests of the Anchieta Island, Brazil in order to understand how plant communities reassemble following human disturbances as well as to determine suitable strategies of forest restoration. The fields were classified into three vegetation types according to the dominant plant species in: 1) Miconia albicans (Sw.) Triana (Melastomataceae) fields, 2) Dicranopteris flexuosa (Schrader) Underw. (Gleicheniaceae) thickets, and 3) Gleichenella pectinata (Willd.) Ching. (Gleicheniaceae) thickets. Both composition and structure of natural regeneration were compared among the three dominant vegetation types by establishing randomly three plots of 1 x 3 m in five sites of the island. A gradient in composition and abundance of species in natural regeneration could be observed along vegetation types from Dicranopteris fern thickets to Miconia fields. The gradient did not accurately follow the pattern of spatial distribution of the three dominant vegetation types in the island regarding their proximity of the remnant forests. A complex association of biotic and abiotic factors seems to be affecting the seedling recruitment and establishment in the study plots. The lowest plant regeneration found in Dicranopteris and Gleichenella thickets suggests that the ferns inhibit the recruitment of woody and herbaceous species. Otherwise, we could not distinguish different patterns of tree regeneration among the three vegetation types. Our results showed that forest recovery following severe anthropogenic disturbances is not direct, predictable or even achievable on its own. Appropriated actions and methods such as fern removal, planting ground covers, and enrichment planting with tree species were suggested in order to restore the natural forest regeneration process in the abandoned old fields.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The Atlantic Forest is an excellent case study for the elevational diversity of birds, and some inventories along elevational gradients have been carried out in Brazil. Since none of these studies explain the patterns of species richness with elevation, we herein review all Brazilian studies on bird elevational diversity, and test a geometric constraint null model that predicts a unimodal species-altitude curve, the Mid-domain Effect (MDE). We searched for bird inventories in the literature and also analysed our own survey data using limited-radius point counts along an 800 m elevational gradient in the state of São Paulo, Brazil. We found 10 investigations of elevational diversity of Atlantic Forest birds and identified five different elevational patterns: monotonic decreasing diversity, constant at low elevations, constant at low elevations but increasing towards the middle, and two undescribed patterns for Atlantic Forest birds, trough-shaped and increasing diversity. The average MDE fit was low (r² = 0.31) and none of the MDE predictions were robust across all gradients. Those studies with good MDE model fits had obvious sampling bias. Although it has been proposed that the MDE may be positively associated with the elevational diversity of birds, it does not fit the Brazilian Atlantic Forest bird elevational diversity.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The Brazilian Atlantic Forest harbors the world's richest areas of land planarians (Platyhelminthes: Tricladida). Nevertheless, the number of undiscovered species from this biological unit remains seemingly high. Herein we describe Geoplana piriana Almeida & Carbayo, sp. nov. from the state of Rio de Janeiro, and Geoplana tingauna Kishimoto & Carbayo, sp. nov. from the state of Santa Catarina. Each species shows a dorsum with a unique color pattern among Geoplaninae species. Their internal morphology also differs: G. piriana sp. nov. shows a unique combination of features, including an extrabulbar, non-bifurcated prostatic vesicle, a non-folded male atrium, a horizontal, cylindrical penis papilla, a female atrium anteriorly narrowed, and lined with an epithelium with multilayered aspect. Geoplana tingauna sp. nov. possesses a prostatic vesicle constituted of a pair of branches opening into the very distal portion of a tubular, unpaired portion, a feature not seen in other Geoplaninae species.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The viability and interpretation of techniques for the evaluation of immunocompetence of animals in their natural environment has been largely debated. One of these methods is based on testing the antimicrobial capacity of the blood and/or plasma in vitro, which could rapidly and effectively assess the immunological conditions of natural populations. We tested the applicability of the antimicrobial capacity of plasma (ACP) assay in anuran amphibians from the Atlantic Forest. The assay was performed by measuring both the turbidity (in a spectrophotometer) and the colony forming units (CFU) of the remaining bacteria (Escherichia coli) following exposure to amphibian plasma. Although both assays were correlated, the ACP assay by spectrophotometry showed 10 times lower intra-assay variation. We also found interspecific variation in ACP, as well as the maintenance of ACP values in males from the same population, collected in different breeding seasons. Thus, the estimation of ACP by spectrophotometry provides a convenient and accurate method for evaluating innate immunocompetence in comparative and ecophysiological studies of anuran amphibians.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Conservation and monitoring of forest biodiversity requires reliable information about forest structure and composition at multiple spatial scales. However, detailed data about forest habitat characteristics across large areas are often incomplete due to difficulties associated with field sampling methods. To overcome this limitation we employed a nationally available light detection and ranging (LiDAR) remote sensing dataset to develop variables describing forest landscape structure across a large environmental gradient in Switzerland. Using a model species indicative of structurally rich mountain forests (hazel grouse Bonasa bonasia), we tested the potential of such variables to predict species occurrence and evaluated the additional benefit of LiDAR data when used in combination with traditional, sample plot-based field variables. We calibrated boosted regression trees (BRT) models for both variable sets separately and in combination, and compared the models’ accuracies. While both field-based and LiDAR models performed well, combining the two data sources improved the accuracy of the species’ habitat model. The variables retained from the two datasets held different types of information: field variables mostly quantified food resources and cover in the field and shrub layer, LiDAR variables characterized heterogeneity of vegetation structure which correlated with field variables describing the understory and ground vegetation. When combined with data on forest vegetation composition from field surveys, LiDAR provides valuable complementary information for encompassing species niches more comprehensively. Thus, LiDAR bridges the gap between precise, locally restricted field-data and coarse digital land cover information by reliably identifying habitat structure and quality across large areas.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

To escape certain death during the Nazi regime, approximately eighty thousand terrorized and persecuted Eastern European Jews sought refuge in the forests surrounding their communities. Most often, their forest deaths were the result of Nazi-sponsored activities such as ghetto deportations and hunts for Jewish escapees. However, anti-Semitic partisans, partisan combat, hostile peasants, and environmental elements were also factors contributing to an estimated ninety percent fatality rate. This dissertation explored the role and meaning of forests to these Jewish fugitives. It investigated the bodily and social practices they developed to enhance their odds of survival in the forest landscape. I develop the concept of landscape agency as a response to my research question: What was it like to live and survive (or die) in the forest during the Holocaust? Moreover, it is an approach to theorizing about the humanity of space. Landscape agency builds upon a phenomenological approach to space and place that links landscape and action through bodily practices. This dissertation analyzed the fugitives' actions as functions of various forms of capital, namely economic, cultural and social. The sample included thirteen individuals who were themselves forest fugitives during the Holocaust. Face-face qualitative interviews were conducted from 2004 to 2006. Primary data from these interviews was used extensively to demonstrate the practices utilized in the fugitives' experiences with life and death in the forest. This study concluded that the odds of survival for forest fugitives were enhanced by use of landscape agency.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Conservation of large felids is not only about collecting ecological information; it is also about understanding people’s values, beliefs, attitudes and behaviour. The overarching goal of this thesis is to assess the relationship between people and jaguars and pumas. Specifically by contributing to the understanding of public acceptance of big cats, as well as the forces (cognitive and social) that influence people’s acceptability. Self-administered questionnaires (n=326) were applied to rural residents outside two protected areas in the State of Sao Paulo: Intervales and PETAR state parks. Findings showed that the acceptability of killing big cats varied accordingly to attitudinal type (positive and negative). Additionally, acceptability of jaguars and pumas was influenced by existence values, attitudes and park credibility. Human dimensions research helped in understanding the relationship between people and the big cats, highlighting the need, for example, to improve the credibility of the parks in the communities and to decrease the fear of jaguars and pumas.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The essential oil obtained by hydrodistillation of fresh leaves of Psidium cattleianum Sabine, collected in the Atlantic Forest in southeastern Brazil, was analyzed by GC and GC/MS. The oil had the main constituents alpha-thujene (25.2%), 1,8-cineole (16.4%) and beta-caryophyllene (10.2%).

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Ecological systems are vulnerable to irreversible change when key system properties are pushed over thresholds, resulting in the loss of resilience and the precipitation of a regime shift. Perhaps the most important of such properties in human-modified landscapes is the total amount of remnant native vegetation. In a seminal study Andren proposed the existence of a fragmentation threshold in the total amount of remnant vegetation, below which landscape-scale connectivity is eroded and local species richness and abundance become dependent on patch size. Despite the fact that species patch-area effects have been a mainstay of conservation science there has yet to be a robust empirical evaluation of this hypothesis. Here we present and test a new conceptual model describing the mechanisms and consequences of biodiversity change in fragmented landscapes, identifying the fragmentation threshold as a first step in a positive feedback mechanism that has the capacity to impair ecological resilience, and drive a regime shift in biodiversity. The model considers that local extinction risk is defined by patch size, and immigration rates by landscape vegetation cover, and that the recovery from local species losses depends upon the landscape species pool. Using a unique dataset on the distribution of non-volant small mammals across replicate landscapes in the Atlantic forest of Brazil, we found strong evidence for our model predictions - that patch-area effects are evident only at intermediate levels of total forest cover, where landscape diversity is still high and opportunities for enhancing biodiversity through local management are greatest. Furthermore, high levels of forest loss can push native biota through an extinction filter, and result in the abrupt, landscape-wide loss of forest-specialist taxa, ecological resilience and management effectiveness. The proposed model links hitherto distinct theoretical approaches within a single framework, providing a powerful tool for analysing the potential effectiveness of management interventions.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)